Great post, Mordy, and I do agree that human supplements are generally better. I did not read through all of the posts, so forgive me if this information is repeated, but, please keep in mind that when looking at the recommended dosage on the supplement bottles, these recommendations are based upon the average adult human being, based upon an average weight of 150 lbs so dosages given to dogs should be adjusted according to weight.
Also, I will argue the fact about carbs not feeding yeast infections - starches are typically converted to sugar by the body, therefore, do indeed feed yeast problems - especially systematic yeast problems. However, I will agree that fruits and vegetables do also need to be eliminated or greatly reduced in the diet as they, too, contain carbs in the form of sugars.
My Newfoundland had a terrible time with yeast - anytime she has pasta, rice, potato, too many fruits or veggies, etc., she does end up with yeast rashes. Quite simply, she is now on a fresh carnivore diet and is supplemented with probiotics if she ends up consuming any of the high-carb foods. She cannot at all eat regular kibble.
Also, unless it's a matter of life and death, she does not ever get antibiotics, steroids, etc.